src/loader/Interpreter.cpp

   1 /*
   2  * Interpreter.cpp
   3  *
   4  *  Created on: Aug 26, 2012
   5  *      Author: holy
   6  */
   7
   8 #include "Interpreter.h"
   9
  10 #include "ParsedSource.h"
  11 #include "../battle/Hero.h"
  12 #include "../battle/Monster.h"
  13 #include "../battle/PartyLayout.h"
  14 #include "../battle/Resources.h"
  15 #include "../common/Ikari.h"
  16 #include "../common/Item.h"
  17 #include "../common/Script.h"
  18 #include "../common/Spell.h"
  19 #include "../common/Stats.h"
  20 #include "../common/TargetingMode.h"
  21 #include "../graphics/ComplexAnimation.h"
  22 #include "../graphics/Font.h"
  23 #include "../graphics/Frame.h"
  24 #include "../graphics/Gauge.h"
  25 #include "../graphics/Menu.h"
  26 #include "../graphics/SimpleAnimation.h"
  27 #include "../graphics/Sprite.h"
  28
  29 #include <algorithm>
  30 #include <cstring>
  31 #include <SDL_image.h>
  32
  33 using battle::Hero;
  34 using battle::Monster;
  35 using battle::PartyLayout;
  36 using common::Ikari;
  37 using common::Item;
  38 using common::Script;
  39 using common::Spell;
  40 using common::Stats;
  41 using common::TargetingMode;
  42 using graphics::Animation;
  43 using graphics::Color;
  44 using graphics::Font;
  45 using graphics::Frame;
  46 using graphics::Gauge;
  47 using graphics::ComplexAnimation;
  48 using graphics::SimpleAnimation;
  49 using graphics::Sprite;
  50 using geometry::Vector;
  51 using std::make_pair;
  52 using std::set;
  53 using std::string;
  54 using std::vector;
  55
  56 namespace loader {
  57
  58 Interpreter::~Interpreter() {
  59         for (std::map<string, SDL_Surface *>::const_iterator i(imageCache.begin()), end(imageCache.end()); i != end; ++i) {
  60                 SDL_FreeSurface(i->second);
  61         }
  62 }
  63
  64
  65 const Interpreter::ParsedDefinition &Interpreter::GetDefinition(const string &identifier) {
  66         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(identifier));
  67         if (i != parsedDefinitions.end()) {
  68                 return i->second;
  69         } else if (source.IsDefined(identifier)) {
  70                 ReadDefinition(source.GetDefinition(identifier));
  71                 return parsedDefinitions.at(identifier);
  72         } else {
  73                 throw Error("access to undefined object " + identifier);
  74         }
  75 }
  76
  77
  78 void *Interpreter::GetObject(int typeId, const std::string &name) {
  79         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(name));
  80         if (i != parsedDefinitions.end()) {
  81                 const TypeDescription &requested(TypeDescription::Get(typeId));
  82                 const TypeDescription &actual(TypeDescription::Get(i->second.type));
  83                 if (requested.TypeId() == actual.TypeId()) {
  84                         return values[actual.TypeId()][i->second.id];
  85                 } else if (actual.IsSubtypeOf(requested)) {
  86                         char *sub(reinterpret_cast<char *>(values[actual.TypeId()][i->second.id]));
  87                         std::ptrdiff_t offset(actual.SupertypeOffset(requested));
  88                         return sub - offset;
  89                 } else {
  90                         throw Error("cannot cast " + actual.TypeName() + " to " + requested.TypeName());
  91                 }
  92         } else {
  93                 throw Error("access to undefined object " + name);
  94         }
  95 }
  96
  97
  98 void Interpreter::ReadSource() {
  99         for (set<string>::const_iterator i(source.Exports().begin()), end(source.Exports().end()); i != end; ++i) {
 100                 ReadDefinition(source.GetDefinition(*i));
 101         }
 102 }
 103
 104 void Interpreter::ReadDefinition(const Definition &dfn) {
 105         if (parsedDefinitions.find(dfn.Identifier()) != parsedDefinitions.end()) {
 106                 return;
 107         }
 108         if (dfn.HasLiteralValue()) {
 109                 ReadLiteral(dfn);
 110         } else {
 111                 ReadObject(dfn);
 112         }
 113 }
 114
 115 void Interpreter::ReadLiteral(const Definition &dfn) {
 116         const string &typeName(dfn.GetLiteral()->IsArray() ? "Array" : dfn.GetLiteral()->GetTypeName());
 117         int typeId(TypeDescription::GetTypeId(typeName));
 118         int id(values[typeId].size());
 119         const TypeDescription &td(TypeDescription::Get(typeId));
 120         int size(
 121                         (dfn.GetLiteral()->GetType() == Literal::PATH
 122                                         || dfn.GetLiteral()->GetType() == Literal::STRING)
 123                         ? dfn.GetLiteral()->GetString().size() : td.Size());
 124         char *object(alloc.Alloc(size));
 125         values[typeId].push_back(object);
 126         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 127         if (dfn.GetLiteral()->GetType() == Literal::OBJECT) {
 128                 ReadObject(typeId, id, object, *dfn.GetLiteral()->GetProperties());
 129         } else {
 130                 ReadLiteral(typeId, id, object, *dfn.GetLiteral());
 131         }
 132 }
 133
 134 void Interpreter::ReadLiteral(int typeId, int id, char *object, const Literal &literal) {
 135         switch (literal.GetType()) {
 136                 case Literal::ARRAY_VALUES:
 137                         throw Error("named value arrays are not supported, sorry");
 138                         break;
 139                 case Literal::ARRAY_PROPS:
 140                         throw Error("named property list arrays are not supported, sorry");
 141                         break;
 142                 case Literal::BOOLEAN:
 143                         new (object) bool(literal.GetBoolean());
 144                         break;
 145                 case Literal::COLOR:
 146                         new (object) Color(literal.GetRed(), literal.GetGreen(), literal.GetBlue(), literal.GetAlpha());
 147                         break;
 148                 case Literal::NUMBER:
 149                         new (object) int(literal.GetNumber());
 150                         break;
 151                 case Literal::PATH:
 152                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 153                         object[literal.GetString().size()] = '\0';
 154                         break;
 155                 case Literal::SCRIPT:
 156                         new (object) Script;
 157                         ReadScript(literal.GetScript(), reinterpret_cast<Script *>(object));
 158                         break;
 159                 case Literal::STRING:
 160                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 161                         object[literal.GetString().size()] = '\0';
 162                         break;
 163                 case Literal::VECTOR:
 164                         new (object) Vector<int>(literal.GetX(), literal.GetY());
 165                         break;
 166                 case Literal::OBJECT:
 167                         throw Error("illogical branch: read literal object as non-object literal");
 168         }
 169 }
 170
 171
 172 void *Interpreter::GetObject(int typeId, const Value &v) {
 173         if (v.IsLiteral()) {
 174                 if (v.GetLiteral().IsObject()) {
 175                         int typeId(TypeDescription::GetTypeId(v.GetLiteral().GetTypeName()));
 176                         const TypeDescription &td(TypeDescription::Get(typeId));
 177                         char *object(alloc.Alloc(td.Size()));
 178                         td.Construct(object);
 179                         int id(values[typeId].size());
 180                         values[typeId].push_back(object);
 181                         ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 182                         return object;
 183                 } else {
 184                         int typeId(0), id(0);
 185                         switch (v.GetLiteral().GetType()) {
 186                                 case Literal::ARRAY_VALUES:
 187                                         throw Error("cannot copy value arrays, sorry");
 188                                         break;
 189                                 case Literal::ARRAY_PROPS:
 190                                         throw Error("cannot copy property list arrays, sorry");
 191                                         break;
 192                                 case Literal::BOOLEAN:
 193                                         {
 194                                                 typeId = TypeDescription::GetTypeId("Boolean");
 195                                                 id = values[typeId].size();
 196                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 197                                                 char *object(alloc.Alloc(td.Size()));
 198                                                 values[typeId].push_back(new (object) bool(v.GetLiteral().GetBoolean()));
 199                                         }
 200                                         break;
 201                                 case Literal::COLOR:
 202                                         {
 203                                                 typeId = TypeDescription::GetTypeId("Color");
 204                                                 id = values[typeId].size();
 205                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 206                                                 char *object(alloc.Alloc(td.Size()));
 207                                                 values[typeId].push_back(new (object) Color(v.GetLiteral().GetRed(), v.GetLiteral().GetGreen(), v.GetLiteral().GetBlue(), v.GetLiteral().GetAlpha()));
 208                                         }
 209                                         break;
 210                                 case Literal::NUMBER:
 211                                         {
 212                                                 typeId = TypeDescription::GetTypeId("Number");
 213                                                 id = values[typeId].size();
 214                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 215                                                 char *object(alloc.Alloc(td.Size()));
 216                                                 values[typeId].push_back(new (object) int(v.GetLiteral().GetNumber()));
 217                                         }
 218                                         break;
 219                                 case Literal::PATH:
 220                                         {
 221                                                 typeId = TypeDescription::GetTypeId("Path");
 222                                                 id = values[typeId].size();
 223                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 224                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 225                                                 str[v.GetLiteral().GetString().size()] = '\0';
 226                                                 values[typeId].push_back(str);
 227                                         }
 228                                         break;
 229                                 case Literal::SCRIPT:
 230                                         {
 231                                                 typeId = TypeDescription::GetTypeId("Script");
 232                                                 char *script(ReadScript(v.GetLiteral().GetScript()));
 233                                                 id = values[typeId].size();
 234                                                 values[typeId].push_back(script);
 235                                         }
 236                                         break;
 237                                 case Literal::STRING:
 238                                         {
 239                                                 typeId = TypeDescription::GetTypeId("String");
 240                                                 id = values[typeId].size();
 241                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 242                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 243                                                 str[v.GetLiteral().GetString().size()] = '\0';
 244                                                 values[typeId].push_back(str);
 245                                         }
 246                                         break;
 247                                 case Literal::VECTOR:
 248                                         {
 249                                                 typeId = TypeDescription::GetTypeId("Vector");
 250                                                 id = values[typeId].size();
 251                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 252                                                 char *object(alloc.Alloc(td.Size()));
 253                                                 values[typeId].push_back(new (object) Vector<int>(v.GetLiteral().GetX(), v.GetLiteral().GetY()));
 254                                         }
 255                                         break;
 256                                 case Literal::OBJECT:
 257                                         {
 258                                                 typeId = TypeDescription::GetTypeId(v.GetLiteral().GetTypeName());
 259                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 260                                                 id = values[typeId].size();
 261                                                 char *object(alloc.Alloc(td.Size()));
 262                                                 td.Construct(object);
 263                                                 ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 264                                         }
 265                                         break;
 266                         }
 267                         return values[typeId][id];
 268                 }
 269         } else {
 270                 ReadDefinition(source.GetDefinition(v.GetIdentifier()));
 271                 return GetObject(typeId, v.GetIdentifier());
 272         }
 273 }
 274
 275
 276 void Interpreter::ReadObject(const Definition &dfn) {
 277         int typeId(TypeDescription::GetTypeId(dfn.TypeName()));
 278         const TypeDescription &td(TypeDescription::Get(typeId));
 279         int id(values[typeId].size());
 280         char *object(alloc.Alloc(td.Size()));
 281         td.Construct(object);
 282         values[typeId].push_back(object);
 283         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 284         ReadObject(typeId, id, object, *dfn.GetProperties());
 285 }
 286
 287
 288 void Interpreter::ReadObject(int typeId, int id, char *object, const PropertyList &props) {
 289         const TypeDescription &td(TypeDescription::Get(typeId));
 290         for (PropertyList::ConstIterator i(props.Begin()), end(props.End()); i != end; ++i) {
 291                 const FieldDescription &fd(td.GetField(i->first));
 292                 const TypeDescription &fieldType(TypeDescription::Get(fd.TypeId()));
 293                 if (CanLink(*i->second)) {
 294                         char *dest(object + fd.Offset());
 295                         if (fd.IsAggregate()) {
 296                                 int arraySize(i->second->GetLiteral().ArraySize());
 297                                 char *aggregate(alloc.Alloc(fieldType.Size() * arraySize));
 298                                 char *iter(aggregate);
 299                                 if (i->second->GetLiteral().GetType() == Literal::ARRAY_PROPS) {
 300                                         const vector<PropertyList *> &list(i->second->GetLiteral().GetPropertyLists());
 301                                         for (vector<PropertyList *>::const_iterator j(list.begin()), end(list.end()); j != end; ++j, iter += fieldType.Size()) {
 302                                                 fieldType.Construct(iter);
 303                                                 ReadObject(fieldType.TypeId(), -1, iter, **j);
 304                                         }
 305                                 } else {
 306                                         const vector<Value *> &list(i->second->GetLiteral().GetValues());
 307                                         for (vector<Value *>::const_iterator j(list.begin()), end(list.end()); j != end; ++j, iter += fieldType.Size()) {
 308                                                 fieldType.Construct(iter);
 309                                                 ReadLiteral(fieldType.TypeId(), -1, iter, (*j)->GetLiteral());
 310                                         }
 311                                 }
 312                                 if (fd.IsReferenced()) {
 313                                         std::memcpy(dest, &aggregate, sizeof(char *));
 314                                         dest += sizeof(char *);
 315                                         std::memcpy(dest, &arraySize, sizeof(int));
 316                                 } else {
 317                                         throw Error("aggregate type fields must be referenced");
 318                                 }
 319                         } else if (i->second->IsLiteral() && !fd.IsReferenced()) {
 320                                 // inline literals
 321                                 if (i->second->GetLiteral().IsObject()) {
 322                                         ReadObject(fd.TypeId(), -1, dest, *i->second->GetLiteral().GetProperties());
 323                                 } else {
 324                                         ReadLiteral(fd.TypeId(), -1, dest, i->second->GetLiteral());
 325                                 }
 326                         } else {
 327                                 char *src(reinterpret_cast<char *>(GetObject(fd.TypeId(), *i->second)));
 328                                 if (fd.TypeId() == TypeDescription::GetTypeId("Image")) {
 329                                         src = reinterpret_cast<char *>(GetImage(src));
 330                                 }
 331                                 if (fd.IsReferenced()) {
 332                                         std::memcpy(dest, &src, sizeof(char *));
 333                                 } else {
 334                                         std::memcpy(dest, src, fieldType.Size());
 335                                 }
 336                         }
 337                 } else {
 338                         Postpone(typeId, id, fd.Offset(), i->second->GetIdentifier(), fd.TypeId(), !fd.IsReferenced());
 339                 }
 340         }
 341         td.Load(object);
 342 }
 343
 344
 345 void Interpreter::ReadScript(const std::vector<ScriptToken *> &s, Script *script) {
 346         std::map<string, int> labels;
 347         int size(0);
 348         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 349                 if ((*i)->GetType() == ScriptToken::LABEL) {
 350                         if (labels.count((*i)->Label())) {
 351                                 throw Error("duplicate label " + (*i)->Label());
 352                         } else {
 353                                 labels[(*i)->Label()] = size;
 354                         }
 355                 } else if ((*i)->GetType() != ScriptToken::COMMAND) {
 356                         throw Error("unexpected script token");
 357                 }
 358                 ++size;
 359                 const string &cmd((*i)->CommandName());
 360                 if (cmd == "move") {
 361                         ++i;
 362                         if (i == end) {
 363                                 throw Error("unexpected script end after move");
 364                         }
 365                         const string &reg((*i)->RegisterName());
 366                         switch (reg[0]) {
 367                                 case 'a':
 368                                         size += sizeof(void *);
 369                                         break;
 370                                 case 'i':
 371                                         size += sizeof(int);
 372                                         break;
 373                                 case 'v':
 374                                         size += sizeof(Vector<int>);
 375                                         break;
 376                                 default:
 377                                         throw Error("unknown register " + reg);
 378                         }
 379                         ++i;
 380                         if (i == end) {
 381                                 throw Error("unexpected script end after move");
 382                         }
 383                 } else if (cmd == "add") {
 384                         ++i;
 385                         if (i == end) {
 386                                 throw Error("unexpected script end after add");
 387                         }
 388                         const string &reg((*i)->RegisterName());
 389                         switch (reg[0]) {
 390                                 case 'i':
 391                                         size += sizeof(int);
 392                                         break;
 393                                 case 'v':
 394                                         size += sizeof(Vector<int>);
 395                                         break;
 396                                 default:
 397                                         throw Error("expected register after add " + reg);
 398                         }
 399                         ++i;
 400                         if (i == end) {
 401                                 throw Error("unexpected script end after add");
 402                         }
 403                 } else if (cmd == "mod") {
 404                         ++i;
 405                         if (i == end) {
 406                                 throw Error("unexpected script end after mod");
 407                         }
 408                         size += sizeof(int);
 409                         ++i;
 410                         if (i == end) {
 411                                 throw Error("unexpected script end after mod");
 412                         }
 413                 } else if (cmd == "rand") {
 414                         ++i;
 415                         if (i == end) {
 416                                 throw Error("unexpected script end after rand");
 417                         }
 418                         size += sizeof(int);
 419                         ++i;
 420                         if (i == end) {
 421                                 throw Error("unexpected script end after rand");
 422                         }
 423                 } else if (cmd == "cmp") {
 424                         ++i;
 425                         if (i == end) {
 426                                 throw Error("unexpected script end after cmp");
 427                         }
 428                         size += sizeof(int);
 429                         ++i;
 430                         if (i == end) {
 431                                 throw Error("unexpected script end after cmp");
 432                         }
 433                 } else if (cmd == "jmp") {
 434                         size += sizeof(int);
 435                         ++i;
 436                         if (i == end) {
 437                                 throw Error("unexpected script end after cmp");
 438                         }
 439                 } else if (cmd == "jeq") {
 440                         size += sizeof(int);
 441                         ++i;
 442                         if (i == end) {
 443                                 throw Error("unexpected script end after cmp");
 444                         }
 445                 } else if (cmd == "jne") {
 446                         size += sizeof(int);
 447                         ++i;
 448                         if (i == end) {
 449                                 throw Error("unexpected script end after cmp");
 450                         }
 451                 } else if (cmd == "jl") {
 452                         size += sizeof(int);
 453                         ++i;
 454                         if (i == end) {
 455                                 throw Error("unexpected script end after cmp");
 456                         }
 457                 } else if (cmd == "jle") {
 458                         size += sizeof(int);
 459                         ++i;
 460                         if (i == end) {
 461                                 throw Error("unexpected script end after cmp");
 462                         }
 463                 } else if (cmd == "jg") {
 464                         size += sizeof(int);
 465                         ++i;
 466                         if (i == end) {
 467                                 throw Error("unexpected script end after cmp");
 468                         }
 469                 } else if (cmd == "jge") {
 470                         size += sizeof(int);
 471                         ++i;
 472                         if (i == end) {
 473                                 throw Error("unexpected script end after cmp");
 474                         }
 475                 } else if (cmd == "sysc") {
 476
 477                 } else {
 478                         throw Error("unknown command " + cmd);
 479                 }
 480         }
 481
 482         unsigned char *text(reinterpret_cast<unsigned char *>(alloc.Alloc(size)));
 483         int cursor(0);
 484         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 485                 if ((*i)->GetType() == ScriptToken::LABEL) {
 486                         continue;
 487                 }
 488                 if ((*i)->GetType() != ScriptToken::COMMAND) {
 489                         throw Error("unexpected script token");
 490                 }
 491                 const string &cmd((*i)->CommandName());
 492                 if (cmd == "move") {
 493                         ++i;
 494                         const string &reg((*i)->RegisterName());
 495                         ++i;
 496                         if (reg == "a0") {
 497                                 text[cursor] = Script::CODE_MOVE_A0;
 498                                 ++cursor;
 499                                 ReadScriptAddress(**i, text + cursor);
 500                                 cursor += sizeof(void *);
 501                         } else if (reg == "a1") {
 502                                 text[cursor] = Script::CODE_MOVE_A1;
 503                                 ++cursor;
 504                                 ReadScriptAddress(**i, text + cursor);
 505                                 cursor += sizeof(void *);
 506                         } else if (reg == "i0") {
 507                                 text[cursor] = Script::CODE_MOVE_I0;
 508                                 ++cursor;
 509                                 ReadScriptInteger(**i, text + cursor);
 510                                 cursor += sizeof(int);
 511                         } else if (reg == "i1") {
 512                                 text[cursor] = Script::CODE_MOVE_I1;
 513                                 ++cursor;
 514                                 ReadScriptInteger(**i, text + cursor);
 515                                 cursor += sizeof(int);
 516                         } else if (reg == "v0") {
 517                                 text[cursor] = Script::CODE_MOVE_V0;
 518                                 ++cursor;
 519                                 ReadScriptVector(**i, text + cursor);
 520                                 cursor += sizeof(Vector<int>);
 521                         } else if (reg == "v1") {
 522                                 text[cursor] = Script::CODE_MOVE_V1;
 523                                 ++cursor;
 524                                 ReadScriptVector(**i, text + cursor);
 525                                 cursor += sizeof(Vector<int>);
 526                         } else {
 527                                 throw Error("unknown register " + reg);
 528                         }
 529                 } else if (cmd == "add") {
 530                         ++i;
 531                         const string &reg((*i)->RegisterName());
 532                         ++i;
 533                         if (reg == "i0") {
 534                                 text[cursor] = Script::CODE_ADD_I0;
 535                                 ++cursor;
 536                                 ReadScriptInteger(**i, text + cursor);
 537                                 cursor += sizeof(int);
 538                         } else if (reg == "i1") {
 539                                 text[cursor] = Script::CODE_ADD_I1;
 540                                 ++cursor;
 541                                 ReadScriptInteger(**i, text + cursor);
 542                                 cursor += sizeof(int);
 543                         } else if (reg == "v0") {
 544                                 text[cursor] = Script::CODE_ADD_V0;
 545                                 ++cursor;
 546                                 ReadScriptVector(**i, text + cursor);
 547                                 cursor += sizeof(Vector<int>);
 548                         } else if (reg == "v1") {
 549                                 text[cursor] = Script::CODE_ADD_V1;
 550                                 ++cursor;
 551                                 ReadScriptVector(**i, text + cursor);
 552                                 cursor += sizeof(Vector<int>);
 553                         } else {
 554                                 throw Error("unexpected register " + reg);
 555                         }
 556                 } else if (cmd == "mod") {
 557                         ++i;
 558                         const string &reg((*i)->RegisterName());
 559                         ++i;
 560                         if (reg == "i0") {
 561                                 text[cursor] = Script::CODE_MOD_I0;
 562                                 ++cursor;
 563                                 ReadScriptInteger(**i, text + cursor);
 564                                 cursor += sizeof(int);
 565                         } else if (reg == "i1") {
 566                                 text[cursor] = Script::CODE_MOD_I1;
 567                                 ++cursor;
 568                                 ReadScriptInteger(**i, text + cursor);
 569                                 cursor += sizeof(int);
 570                         } else {
 571                                 throw Error("unexpected register " + reg);
 572                         }
 573                 } else if (cmd == "rand") {
 574                         ++i;
 575                         const string &reg((*i)->RegisterName());
 576                         if (reg == "i0") {
 577                                 text[cursor] = Script::CODE_RAND_I0;
 578                                 ++cursor;
 579                         } else if (reg == "i1") {
 580                                 text[cursor] = Script::CODE_RAND_I1;
 581                                 ++cursor;
 582                         } else {
 583                                 throw Error("unexpected register " + reg);
 584                         }
 585                 } else if (cmd == "cmp") {
 586                         ++i;
 587                         const string &reg((*i)->RegisterName());
 588                         ++i;
 589                         if (reg == "i0") {
 590                                 if ((*i)->GetType() == ScriptToken::REGISTER && (*i)->RegisterName() == "i1") {
 591                                         text[cursor] = Script::CODE_CMP_I0_I1;
 592                                         ++cursor;
 593                                 } else {
 594                                         text[cursor] = Script::CODE_CMP_I0;
 595                                         ++cursor;
 596                                         ReadScriptInteger(**i, text + cursor);
 597                                         cursor += sizeof(int);
 598                                 }
 599                         } else if (reg == "i1") {
 600                                 text[cursor] = Script::CODE_CMP_I1;
 601                                 ++cursor;
 602                                 ReadScriptInteger(**i, text + cursor);
 603                                 cursor += sizeof(int);
 604                         } else {
 605                                 throw Error("cannot use " + reg + " as lhs for comparison");
 606                         }
 607                 } else if (cmd == "jmp") {
 608                         text[cursor] = Script::CODE_JUMP;
 609                         ++cursor;
 610                         ++i;
 611                         if (!labels.count((*i)->Identifier())) {
 612                                 throw Error("use of undefined label " + (*i)->Identifier());
 613                         }
 614                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 615                         cursor += sizeof(int);
 616                 } else if (cmd == "jeq") {
 617                         text[cursor] = Script::CODE_JUMP_EQUAL;
 618                         ++cursor;
 619                         ++i;
 620                         if (!labels.count((*i)->Identifier())) {
 621                                 throw Error("use of undefined label " + (*i)->Identifier());
 622                         }
 623                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 624                         cursor += sizeof(int);
 625                 } else if (cmd == "jne") {
 626                         text[cursor] = Script::CODE_JUMP_NOT_EQUAL;
 627                         ++cursor;
 628                         ++i;
 629                         if (!labels.count((*i)->Identifier())) {
 630                                 throw Error("use of undefined label " + (*i)->Identifier());
 631                         }
 632                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 633                         cursor += sizeof(int);
 634                 } else if (cmd == "jl") {
 635                         text[cursor] = Script::CODE_JUMP_LESS;
 636                         ++cursor;
 637                         ++i;
 638                         if (!labels.count((*i)->Identifier())) {
 639                                 throw Error("use of undefined label " + (*i)->Identifier());
 640                         }
 641                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 642                         cursor += sizeof(int);
 643                 } else if (cmd == "jle") {
 644                         text[cursor] = Script::CODE_JUMP_LESS_EQUAL;
 645                         ++cursor;
 646                         ++i;
 647                         if (!labels.count((*i)->Identifier())) {
 648                                 throw Error("use of undefined label " + (*i)->Identifier());
 649                         }
 650                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 651                         cursor += sizeof(int);
 652                 } else if (cmd == "jg") {
 653                         text[cursor] = Script::CODE_JUMP_GREATER;
 654                         ++cursor;
 655                         ++i;
 656                         if (!labels.count((*i)->Identifier())) {
 657                                 throw Error("use of undefined label " + (*i)->Identifier());
 658                         }
 659                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 660                         cursor += sizeof(int);
 661                 } else if (cmd == "jge") {
 662                         text[cursor] = Script::CODE_JUMP_GREATER_EQUAL;
 663                         ++cursor;
 664                         ++i;
 665                         if (!labels.count((*i)->Identifier())) {
 666                                 throw Error("use of undefined label " + (*i)->Identifier());
 667                         }
 668                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 669                         cursor += sizeof(int);
 670                 } else if (cmd == "sysc") {
 671                         text[cursor] = Script::CODE_SYSCALL;
 672                         ++cursor;
 673                 } else {
 674                         throw Error("unknown command " + cmd);
 675                 }
 676         }
 677
 678         script->text = text;
 679         script->textlen = size;
 680 }
 681
 682 char *Interpreter::ReadScript(const vector<ScriptToken *> &s) {
 683         char *mem(alloc.Alloc(sizeof(Script)));
 684         new (mem) Script;
 685         Script *script(reinterpret_cast<Script *>(mem));
 686         ReadScript(s, script);
 687         return mem;
 688 }
 689
 690 void Interpreter::ReadScriptAddress(const ScriptToken &t, unsigned char *dest) {
 691         if (t.GetType() != ScriptToken::IDENTIFIER) {
 692                 throw Error("expected identifier for address");
 693         }
 694         if (source.IsDefined(t.Identifier())) {
 695                 const ParsedDefinition &def(GetDefinition(t.Identifier()));
 696                 void *addr(GetObject(def.type, t.Identifier()));
 697                 *reinterpret_cast<void **>(dest) = addr;
 698         } else {
 699                 throw Error("postponing values in scripts not implemented");
 700         }
 701 }
 702
 703 void Interpreter::ReadScriptInteger(const ScriptToken &t, unsigned char *dest) {
 704         if (t.GetType() == ScriptToken::IDENTIFIER) {
 705                 if (source.IsDefined(t.Identifier())) {
 706                         void *num(GetObject(TypeDescription::GetTypeId("Number"), t.Identifier()));
 707                         *reinterpret_cast<int *>(dest) = *reinterpret_cast<int *>(num);
 708                 } else {
 709                         throw Error("postponing values in scripts not implemented");
 710                 }
 711         } else if (t.GetType() == ScriptToken::LITERAL) {
 712                 *reinterpret_cast<int *>(dest) = t.GetLiteral()->GetNumber();
 713         } else {
 714                 throw Error("expected identifier or integer literal");
 715         }
 716 }
 717
 718 void Interpreter::ReadScriptVector(const ScriptToken &t, unsigned char *dest) {
 719         if (t.GetType() == ScriptToken::IDENTIFIER) {
 720                 if (source.IsDefined(t.Identifier())) {
 721                         void *vec(GetObject(TypeDescription::GetTypeId("Vector"), t.Identifier()));
 722                         *reinterpret_cast<Vector<int> *>(dest) = *reinterpret_cast<Vector<int> *>(vec);
 723                 } else {
 724                         throw Error("postponing values in scripts not implemented");
 725                 }
 726         } else if (t.GetType() == ScriptToken::LITERAL) {
 727                 *reinterpret_cast<Vector<int> *>(dest) = Vector<int>(t.GetLiteral()->GetX(), t.GetLiteral()->GetY());
 728         } else {
 729                 throw Error("expected identifier or vector literal");
 730         }
 731 }
 732
 733
 734 SDL_Surface *Interpreter::GetImage(const string &path) {
 735         std::map<string, SDL_Surface *>::const_iterator result(imageCache.find(path));
 736         if (result != imageCache.end()) {
 737                 return result->second;
 738         } else {
 739                 SDL_Surface *image(IMG_Load(path.c_str()));
 740                 imageCache.insert(make_pair(path, image));
 741                 return image;
 742         }
 743 }
 744
 745
 746 bool Interpreter::CanLink(const Value &v) const {
 747         return v.IsLiteral() || source.IsDefined(v.GetIdentifier());
 748 }
 749
 750 void Interpreter::Postpone(int type, int id, std::ptrdiff_t offset, const std::string &identifier, int linkedType, bool inlined) {
 751         char *str(alloc.Alloc(identifier.size() + 1));
 752         std::memcpy(str, identifier.c_str(), identifier.size());
 753         str[identifier.size()] = '\0';
 754         postponedDefinitions.push_back(PostponedDefinition(type, id, offset, str, linkedType, inlined));
 755 }
 756
 757
 758 void Interpreter::CreateTypeDescriptions() {
 759         {
 760                 TypeDescription &td(TypeDescription::Create(BOOLEAN_ID, "Boolean"));
 761                 td.SetDescription("Logical value which can be either true or false.");
 762                 td.SetSize(sizeof(bool));
 763         }
 764         {
 765                 TypeDescription &td(TypeDescription::Create(COLOR_ID, "Color"));
 766                 td.SetDescription(
 767                                 "A color in RGB format with an optional alpha channel.\n"
 768                                 "Components range from 0 to 255.\n"
 769                                 "Alpha defaults to 255 if omitted.");
 770                 td.SetSize(sizeof(Color));
 771         }
 772         {
 773                 TypeDescription &td(TypeDescription::Create(IMAGE_ID, "Image"));
 774                 td.SetDescription("Path to a PNG file with image data.");
 775                 td.SetSize(sizeof(SDL_Surface));
 776         }
 777         {
 778                 TypeDescription &td(TypeDescription::Create(NUMBER_ID, "Number"));
 779                 td.SetDescription("A signed integer.");
 780                 td.SetSize(sizeof(int));
 781         }
 782         {;
 783                 TypeDescription &td(TypeDescription::Create(PATH_ID, "Path"));
 784                 td.SetDescription("A path in the filesystem which is interpreted relative to the source file's location.");
 785                 td.SetSize(1);
 786                 td.AddSupertype(STRING_ID, 0);
 787         }
 788         {
 789                 TypeDescription &td(TypeDescription::Create(SCRIPT_ID, "Script"));
 790                 td.SetDescription("Collection of commands that define a behaviour.");
 791                 td.SetSize(sizeof(Script));
 792         }
 793         {
 794                 TypeDescription &td(TypeDescription::Create(STRING_ID, "String"));
 795                 td.SetDescription("Some characters.");
 796                 td.SetSize(1);
 797         }
 798         {
 799                 TypeDescription &td(TypeDescription::Create(VECTOR_ID, "Vector"));
 800                 td.SetDescription("A pair of numbers usually describing a 2D translation or offset.");
 801                 td.SetSize(sizeof(Vector<int>));
 802         }
 803 }
 804
 805 }